The Sylvian fissure and the island of Reil in the human brain / by D.J. Cunningham.

  • Cunningham, D. J. (Daniel John), 1850-1909.
Date:
[1891?]
Catalogue details

Licence: Public Domain Mark

Credit: The Sylvian fissure and the island of Reil in the human brain / by D.J. Cunningham. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    placed slightly in front of the position which it holds in the female. There is apparently no difference in this respect between the right and left hemispheres. In the Negro it is placed further back than in the European. In the Orang, Chimpanzee, and also in the lower apes, the Sylvian point is placed behind the corresponding point in the human brain, and in this respect the apes resemble more the new-born child than the human adult. It is well known that the posterior horizontal limb of the Sylvian fissure in the last month of intra-uterine development, in the new-born infant and in the young child, lies considerably above the level of the squamous suture, but the relative position which it occupies with reference to this suture at different periods of life has not hitherto been made out. In arriving at the following results, the measurements of the depth of the parietal and temporal lobes, and of the position of the Sylvian fissure with reference to the squamous suture, have been made along a line drawn downwards from the summit of the anterior central convolution, at right angles to the longest antero-posterior axis of the hemisphere. The entire breadth of the hemisphere along this line, from the superior border to the infero-lateral border, is reckoned as being 100. In the advM the fissure was found to be in an equal number of cases a short distance above, a short distance below, and immediately subjacent to the suture. In five hemispheres,/rom children rsinging from 11 to 15 yea/rs, it was found to be in every case above the suture, the average relative distance being S S. In five hemispheres,/rom children ranging from 4i too years, the relative distance of the fissure above the squamous suture was 65. In three hemispheres from children in the first year of life, the relative distance of the fissure above the suture was 136. In six hemispheres from the fvM-time foetus, the relative distance was 20 3. In four hemispheres from foetuses ranging from 7| to 8| Tnonth^, the relative distance was 24. To account for this difforcnce in the position of the Sylvian fissure, with reference to the squamous suture at different periods